Process servers, background checks, skip tracing, and location of missing persons are also carried out by private investigators. In one specific area of specialisation, several departments around the country specialise. Some PI organisations, for instance, only deal with skip tracing, others may specialise in surveillance, and still others may specialise in bug detection, which is the location and disposal of unauthorised types of electronic surveillance often found in cases of corporate spying or dropping personal eves. Fraud investigations, personal security or bodyguard records, and computer forensics, to name a few, are some of the many other specialties a PI may have. Private Investigator Services San Diego offers excellent info on this.

Due to the conditions of the case, private detectives and private investigators frequently work odd hours that enable them to perform surveillance and contact persons who may or may not be available during normal working hours. Work is popular in the early mornings, evenings, weekends and holidays. Most private detectives and private investigators spend most of their time conducting interviews or surveillance away from their offices, but others work most of the day conducting computer searches and making phone calls in their office. Those who have their own agencies and hire other researchers can mainly work in an office and have regular business hours. Sometimes, such as some bodyguard duties for corporate or celebrity clients, an investigation calls for the investigator to be armed. In certain situations, detectives and investigators carrying handguns must be approved to carry a weapon on duty by the required authority. However, a firearm is not required in most situations, since the object of the job is to collect information and not law enforcement or criminal apprehension.

Many states require that licences be issued to private investigators. Some private investigators, while many do not have that kind of technical experience, are former police officers or former military officers. There are strict laws in several states that control and regulate the private investigation sector in the state. A private investigator frequently works long hours, maintains extensive notes and video for reports to supply consumers and often spends much of his time in the field doing surveillance-related work.